Researchers can now collect and sequence DNA from the air

From Live Science.com (Apr. 5, 2021):

We leave DNA all over the place, including in the air, and for the first time, researchers have collected animal DNA from mere air samples, according to a new study.

The DNA that living things, human and otherwise, shed into the environment is called environmental DNA (eDNA). Collecting eDNA from water to learn about the species living there has become fairly common, but until now, no one had attempted to collect animal eDNA from the air.

"What we wanted to know was whether we could filter eDNA from the air to track the presence of terrestrial animals," study author Elizabeth Clare, an ecologist at Queen Mary University of London, said in a video abstract for the study, published Mar. 31 in the journal PeerJ. "We were interested in whether we could use this 'airDNA' as a way to assess what species were present in a burrow or a cave where we could not easily see or capture them," she added.

As a proof-of-concept experiment, Clare and her colleagues tried collecting DNA from the air in an animal facility housing a model organism, the naked mole rat. The researchers detected both human and mole rat DNA in air from both the mole rat enclosures and the room where the enclosures are housed. 

"The demonstration that the DNA from relatively large animals can also be detected in air samples dramatically expands the potential for airborne eDNA analysis," said Matthew Barnes, an ecologist at Texas Tech University, in Lubbock, who was not involved in the new study.

In the last decade, the collection and analysis of eDNA to study and manage plant and animal populations has taken off, Barnes said. "The analogy that I use is like the detective at the crime scene, finding a cigarette butt and swabbing it for DNA to place the criminal at the crime scene. We do that with eDNA except for instead of looking for criminals, we're looking for a rare or elusive species," Barnes said. The species might be endangered or an invasive species new to an environment, he said. [read more]

Interesting. If the CSI:Miami TV drama ever comes back on the air, it could use this tech on an episode.